This invention relates to the recovery of nuclear fuel material from irradiated nuclear fuel elements in which the nuclear fuel is contained in a protective metal sheath and in particular it relates to the recovery of nuclear fuel material from nuclear fuel elements in which the protective metal sheath is manufactured from austenitic stainless steel or austenitic nickel alloy.
Prior to the processing of irradiated nuclear fuel to separate fission products from the nuclear fuel material it is preferable to separate the nuclear fuel material from its protective sheath. It is present practice to shear fuel elements into short lengths mechanically and to dissolve out the fuel material preferentially. However the maintenance of a mechanical shear in a situation where it is exposed to radioactive conditions is difficult and the shearing operation gives rise to dust which contaminates the immediate area around the shear and has to be controlled. After the nuclear fuel material has been dissolved the resulting solution is further processed to separate the fission products from the reusable nuclear fuel material (uranium and plutonium) which is recovered and may be used to manufacture further fuel elements for use in a nuclear reactor. The separation processes are well known in the art and include solvent extraction processes using tributyl phosphate as the extracting agent.